After seeing other people give (great) answers to this, I figured I'd add mine.
1 - Take your time. Your autopilot may be good, but it's not perfect.
2 - Play multiple formats / deck types. In addition to being refreshing, diversity will give you a wider perspective on the game.
3 - Listen to people who (you think) are better than you; ALSO listen to people who (you think) are worse. Being "good at Magic" is a very abstract notion. Different people are good at different aspects of the game and it's common bias to focus on the ones you're already good at.
4 - On that note... Think about all the things outside the game that you can control: sleep, food, music... Improvement at Magic isn't limited to the decks you pick and the plays you make.
5 - In the long run, winning a game matters less than making the right decisions. Making the right decisions matters less than understanding what they were and why. Focus on understanding!
@JEDepraz
#2
for sure, I spent so long only knowing how to play aggro and Strixhavrn limited forced me to learn how to wait and be reactive and focus more on controlling the board. In turn, it made me get better at playing aggro too!